Many electronic systems require or benefit from the use of power delivery devices. For example, electronic systems such as microprocessor-based systems or digital signal processor based systems may require substantial power consumption. Power supply designs with smaller size and higher efficiency are generally more desirable. One type of voltage regulator topology that may meet the high output current demand of some electronic systems is the multiphase interleaved DC-DC converter.
For example, a DC-to-DC converter may include a switch and a low pass filter. Control circuitry may control a duty cycle of the switch so that the output voltage is regulated within a certain range. Typically a free wheeling diode or synchronous switch may be connected between ground and an inductor to provide a current path when the switch is opened. When higher current is required, multiple interleaved phases may be used.
Multiphase interleaving structures may require many inductors. To reduce components count, a coupled magnetic structure may be adopted. Even though the coupled magnetic structure has many advantages, manufacturing some coupled magnetic structures may be relatively complex and some coupled magnetic structures may provide limited design flexibility.
For example, a two-phase converter may be constructed with a toroidal core coupled magnetic structure. Even though the structure is simple, manufacturing may require a special winding tool. A multiphase converter may also be constructed with an H-core coupled magnetic structure. Although manufacturing may be easier than the toroidal approach, design flexibility is limited because the structure uses only a single turn winding (which may make it difficult to provide a high inductance value).